Endoscopy
Introduction
The Endoscopy Division now covers three fields of interest: the gastrointestinal (GI) tract, respiratory system and head and neck. A total of 8,571 endoscopic examinations were performed in 1998, of which 7,570 were GI endoscopy, 755 bronchoscopy, and 246 laryngoscopy. Recently, a remarkable increase has been noted in the number of endoscopic treatments, such as endoscopic mucosal resection (EMR), percutaneous endoscopic gastrostomy (PEG), endoscopic dilatation, and metallic stenting. A high detection rate for esophageal carcinoma at GI endoscopy is a characteristic of our hospital, which is explained by the fact that the large number of head and neck cancer patients who have high risks of combining esophageal cancers are examined at our division.
We have operated a digital filing system for endoscopic images since 1997. The filing system makes it easy to compare new images with old ones of the same patient. The digital images have advantages of high quality resolution and the possibility of long-term preservation. However, this system has several problems yet to be solved; the conference unit is inconvenient and this system is enclosed within our endoscopic room, so that the digital imaging is not available in other divisions. Taking advantage of recent advances in electronic technology, we are planning to introduce a new digital filing system in order to solve these problems.
Routine Activities
An electronic laryngoscope is routinely used in the pretreatment and postoperative evaluations of head and neck cancer patients. We also find it useful in patient education. Examples of recent diagnostic instruments and techniques include ultrathin cholangiopancreatoscopy, metallic stenting for malignant esophageal stenosis, percutaneous endoscopic gastrostomy (PEG) whose aim is to improve the quality of life, and adaptive enhancement by image processing. Endoscopic ultrasonography (EUS) has emerged as a very useful technique for examining GI and peri-gastrointestinal structures. In patients with pancreatic cancer, EUS provides local staging and determination of resectability. EUS-guided fine-needle aspiration or biopsy with visualization of the needle in real-time is gaining popularity for a variety of lesions within the GI wall and outside the GI tract.
Therapeutic frontiers are also being explored by the use of EMR for early mucosal cancers. The percentage of cases treated by EMR has been increasing in early esophageal, gastric and colorectal cancers. This rate is increasing annually due to advances in the diagnosis and expansion of indications. New techniques, such as endoscopic resection using an insulating-tipped diathermic needle knife or the use of clamp laser irradiation with KTP-YAG laser, will continue to push the limits of what can be achieved via an endoscope. In colonoscopy, endoscopic polypectomy and EMR are now performed in 30% of all examinations.
For diagnosis of early lung cancer, lung biopsy under real-time CT fluoroscopic guidence has been performed in a large number of cases, and has yielded promising results. Brachytherapy is applied to relapsed cases of lung cancer with a high response rate.
New Developments
A new endoscopic spectroscopic system (ESS) has been developed for the examination of the spectral characteristics of tissue, especially the reflectance of various lesions in the GI tract. It was evident in our study that each lesion in the stomach had its own peculiar spectral characteristics. Therefore, we suggest that the ESS will become a useful modality for obtaining spectrum data in the GI tract and for clarifying the spectral characteristics of malignant lesions in comparison with any other benign lesions. Light induced autofluorescence endoscopy (LIFE) has been recently developed as a sensitive screening tool for neoplastic lesions of the GI tract. Percutaneous transhepatic cholangioscopy using the LIFE system has been performed for patients with biliary malignancy. Specific fluorescence from cancerous lesions can be differentiated from fluorescence from normal tissue. It has been clarified that adaptive enhancement by image processing is effective for the diagnosis of crypt pattern of colonic tumors, extent of cancerous invasion in early gastric cancer and ulcer staging. Computer analysis of the fine mucosal network pattern by magnifying endoscopy is also studied. These studies along with progress in electronic endoscopy are thought to be the most expected concepts in endoscopic diagnosis. Furthermore, it is very important to develop them for improving the quality of endoscopic diagnosis and for making objective and quantitative diagnosis.
Genetic and immunohistochemical analyses using biopsy specimens have allowed the prediction of chemoresponse and patient survival in advanced esophageal and gastric cancers. We have adapted these methods to study the growth and development of colorectal tumors. In addition, we investigate the correlation between bacterial infection or infectious agents and upper GI carcinogenesis in cooperation with the National Cancer Research Institute.
Statistics
| 1997 | 1998 | |
| Upper gastrointestinal endoscopy | 4265 (111) | 4629 (131) |
| Endoscopic dilation | 133 | 113 |
| Colonoscopy | 2316 (780) | 2441 (711) |
| Endoscopic ultrasonography | 263 | 216 |
| ERCP and cholangioscopy | 81 | 84 |
| Bronchoscopy | 756 | 755 |
| Laryngoscopy | 252 | 246 |
ERCP, endoscopic retrograde cholongiopancreatography.
(H. Tajiri)
